METANOIA/database/artist.go

package database

import (
	"database/sql"
	"encoding/json"
)

type Artist struct {
	Type
	id       int
	metadata []byte
}

type SongArtist struct {
	Artist
	kind string
}

type AlbumArtist struct {
	Artist
	kind string
}

func GetSongArtistFromRow(db *Database, row *sql.Rows) (*SongArtist, error) {
	r := &SongArtist{
		Artist: Artist{
			Type: Type{
				db: db,
			},
		},
	}
	err := row.Scan(&r.id, &r.metadata, &r.kind)
	if err != nil {
		return nil, err
	}
	return r, nil
}

func GetAlbumArtistFromRow(db *Database, row *sql.Rows) (*AlbumArtist, error) {
	r := &AlbumArtist{
		Artist: Artist{
			Type: Type{
				db: db,
			},
		},
	}
	err := row.Scan(&r.id, &r.metadata, &r.kind)
	if err != nil {
		return nil, err
	}
	return r, nil
}

func InsertArtistToDatabase(db *Database, names map[string]string) *Artist {

	//TODO: do it in single tx

	rows, err := db.Query("INSERT INTO artists DEFAULT VALUES RETURNING id;")
	if err != nil {
		return nil
	}
	defer rows.Close()
	rows.Next()
	var id int
	err = rows.Scan(&id)
	if err != nil {
		return nil
	}
	artist := GetArtistFromDatabase(db, id)
	if artist == nil {
		return nil
	}

	for k, n := range names {
		artist.AddName(k, n)
	}

	return artist
}

func GetArtistsFromDatabaseByName(db *Database, name string) (artists []*Artist) {
	rows, err := db.Query("SELECT id, metadata FROM artists WHERE id IN(SELECT artist FROM artists_names WHERE name ILIKE $1);", name)
	if err != nil {
		return nil
	}
	defer rows.Close()
	for rows.Next() {
		artist, err := GetArtistFromRow(db, rows)
		if err != nil {
			break
		}
		artists = append(artists, artist)
	}
	return
}

func GetArtistFromDatabase(db *Database, id int) *Artist {
	rows, err := db.Query("SELECT id, metadata FROM artists WHERE id = $1;", id)
	if err != nil {
		return nil
	}
	defer rows.Close()
	rows.Next()
	r, err := GetArtistFromRow(db, rows)
	if err != nil {
		return nil
	}
	return r
}

func GetArtistFromRow(db *Database, row *sql.Rows) (*Artist, error) {
	r := &Artist{
		Type: Type{
			db: db,
		},
	}
	err := row.Scan(&r.id, &r.metadata)
	if err != nil {
		return nil, err
	}
	return r, nil
}

func (r *Artist) GetId() int {
	return r.id
}

func (r *Artist) GetNames() map[string]string {

	result := make(map[string]string)

	rows, err := r.db.Query("SELECT kind, name FROM artists_names WHERE id $1;", r.id)
	if err != nil {
		return nil
	}
	defer rows.Close()
	for rows.Next() {
		var kind string
		var name string
		err = rows.Scan(&kind, &name)
		if err != nil {
			break
		}
		result[kind] = name
	}

	return result
}

func (r *Artist) RemoveName(kind string) {
	r.db.Exec("DELETE FROM artists_names WHERE id = $1 AND kind = $2;", r.id, kind)
}

func (r *Artist) AddName(kind, name string) {
	r.db.Exec("INSERT INTO artists_names (artist, kind, name) VALUES ($1, $2, $3) ON CONFLICT (artist, kind) DO UPDATE SET name = $3;", r.id, kind, name)
}

func (r *Artist) GetMetadata() (result map[string]interface{}) {
	json.Unmarshal(r.metadata, &result)
	return result
}

func (r *Artist) SetMetadata(value map[string]interface{}) {
	r.metadata, _ = json.Marshal(value)
	r.db.Exec("UPDATE artists SET metadata = $2::jsonb WHERE id = $1;", r.id, r.metadata)
}